The number of solutions of the congruence in the box is estimated from below in the best possible way, provided for all i,j either or or .
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-cm106-2-8, author = {A. Schinzel and M. Zakarczemny}, title = {On a linear homogeneous congruence}, journal = {Colloquium Mathematicae}, volume = {106}, year = {2006}, pages = {283-292}, zbl = {1153.11017}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm106-2-8} }
A. Schinzel; M. Zakarczemny. On a linear homogeneous congruence. Colloquium Mathematicae, Tome 106 (2006) pp. 283-292. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm106-2-8/